The option that BEST describes the impact of the Interstate Commerce Act (1887) on business at the end of the 19th century is:
D While it had little immediate impact, it was the first federal law to put regulations on business in the United States.
The Interstate Commerce Act established the Interstate Commerce Commission (ICC) to regulate railroads and ensure fair rates, but its immediate effects were limited. However, it was significant as it marked the beginning of federal regulation of private industry in the U.S.